Concrete finishing machine



Dec. 4, 1962 Filed Sept. 9, 1957 J- J. MORO LIN ETAL CONCRETE FINISHING MACHINE 2 Sheets-Sheet l INVENTOR JOSEPH J MORO -l u\/ LEVERETTE HDEMNHHUSEfl BY wawpx. M4 man ATTORNEY Dec. 4, 1962' J. J. MORO LIN ETAL 3,

CONCRETE FINISHING MACHINE 2 Sheets-Sheet 2 Filed Sept. 9, 1957 3,066,533 CONQRETE FlNiSHlNG MACHENE Joseph .5. Moro Lin, Glen Rock, and Leverette liloeninghausen. East Paterson, N311, assignors to Kalrnan Floor Company. incorporated, New York, N.Y., a corporation of Delaware Filed Sept. 9, 1957. Ser. No. 682,716 6 Claims. (Cl. 94-45} This invention relates to apparatus for the surfacing of plastic bodies and particularly to apparatus intended to be used for finishing surfaces of concrete slabs such as floor slabs.

Priorly, various types of mechanically operated mechanisms have been developed which were designed and intend-ed to reduce to the minimum the amount of manual labor which must be expended and the time required to reduce to a true plane and impart the desired surface finish to plastic bodies such as concrete floors, walks and roadways. A number of these mechanisms have come into Widespread use, some particularly designed for use on roadways and others primarily intended for employment in the surfacing of floors. A known type of mechanically operated surface mechanism comprises a work engaging member, a motor coupled .to the work engaging member for rotating the work engaging member and a handle which prevents rotation of the motor casing and constitutes a means for moving the implement over the surface of a concrete body in the desired manner.

One particular form of mechanism known in the art includes a mechanism for imparting to the rotating work-engaging member high frequency vibrations so that the plastic body below the apparatus is not only so jected to the action of the rotating disc but is subjected to high frequency vibrations. Such apparatus is highly effective and enables the user to properly surface a plastic body, such as a concrete fioor, in a vastly improved manner. Thus, by the aid of the rotating and vibrating disc, an extremely dry concrete mixture may be surfaced, a mixture having such a low water-cement ratio that it cannot be surfaced by ordinary means or methods since it is impossible to laterally displace or horizontally push material from the higher areas of the concrete onto the lower areas. The leveling of the floor surface is brought about by vertically depressing the higher areas instead of laterally displacing these areas and the concrete slab or the like which is produced is of superior construction, being more dense and free of voids. method of leveling the same results in bringing to the surface a relatively stifif paste of cement and fine sand barely sufficient in thickness for the fine trowelling by hand. The improved method not only gives a superior product but insures substantial surfacing in time and labor costs. However, we have discovered that in employing vibratory and rotary motion to finish the concrete, it is not always necessary to employ both vibratory and rotary motion. For example, after the higher areas are vertically depressed and the plastic body approaches a level surface then the vibratory motion may be discontinued while maintaining the rotary motion to thus achieve an extremely smooth surface. One example of rotary and vibratory surface finishing machine is disclosed and described in detail in R. E. Davis Patent No. 2,386,843, issued October 16, 1945.

Accordingly, it is an object of this invention to provide an improved concrete finishing machine.

It is another object of this invention to provide a cement finishing machine which is adapted selectively to apply vibratory motion to the concrete mass.

It is another object of this invention to provide a The surface is superior inasmuch as this add vibratory-rotary cement finishing machine which is simple in construction and operation.

It is another object of this invention to provide a cement finishing machine in which rotary and vibratory motion are imparted to the concrete mass from a single prime mover and the vibratory motion may be selectively terminated at the will of the operator.

it is another object of this invention to provide a vibratory and rotary cement finishing machine which is simple in construction and operation and thus economical to build.

Briefly, in accordance with aspects of this invention, a cement finishing machine is enclosed in a stationary housing and provided with a cam plate associated with a wear or floor finishing plate. A group of spring biased plungers are mounted on the housing and are opera-tively linked to the cam surfaces by means of rollers mounted on the plungers. The prime mover or source of power for the machine is coupled to the wear plate by means of a splined shaft and a splined plate to impart rotary motion while permitting axial vibratory motion of the wear late. The shaft is spring biased by a helical shock absorber spring secured between the cam or master plate and the end of the shaft. The plungers are moved upwardly by the movement of the rollers upon the cam surfaces and the motion of the plungers may be selectively discontinued by means of pneumatic cylinders and pistons located in the cylinders and each coupled to a plunger. As the cam plate is rotated by means of the splined shaft, the rollers ride the cam surfaces and the connected plungers move out of engagement with the cam plate and return to the cam plate under the influence of the impact springs. Thus, the energy imparted to the impact springs by the cam plate is imparted to the plungers to return the plungers to the cam plate, thereby giving a vibratory motion to the connected wear plate.

In accordance with other aspects of this invention, the plungers may be moved away from the cam or undulation plate by the operator during the finishing operation such that the rollers are disengaged from the cam surfaces. The reciprocating motion of the plungers formerly caused by the cam plate is thus terminated. The operator may thus terminate the vibratory motion imparted to the wear plate and hence to the cement floor without modifying the rotary operation.

In accordance with other aspects of this invention, the plungers are spaced approximately 90 degrees apart on the housing of the machine while opposite pairs of the plungers are oil-set a few degrees so that a beat frequency is generated by the cooperation of the plungers and the cam plate. By means of this beat frequency, the number of vibrations imparted to the wear plate and hence to the floor is greatly increased without the requirement that the wear plate be rotated at exceedingly high speeds.

in accordance with still other aspects of this invention, the cam plate and the wear plate are provided with outer edges formed to project foreign matter from the machine and thus prevent its entry into the machine.

In one exemplary embodiment of the machine, a fluid actuated piston is connected to each of the plungers and the operation of the fiuid actuated piston is controlled through a fluid coupling by a manually operable pump. Actuation of the pump moves the piston upward, raising the plungers to terminate the cooperation between the cam plate and the rollers mounted on the plungers thereby terminating the vibratory motion of the machine.

Accordingly, it is a feature of this invention to provide a cement finishing machine with a cam plate and a reciprocating spring biased plunger operatively connected to the cam plate and to employ a mechanical device adapted to be controlled by the operator to move the plungers out of engagement with the cam plate and thus terminate the vibratory motion of the machine.

It is another feature of this invention to provide a cement finishing machine with a combination of plungers and cam surfaces for imparting vibratory motion to the wear plate of the machine and to provide a mechanical device for controlling the operative engagement and thus the vibrations achieved by the cooperation of the plungers and the cam surfaces.

It is another feature of this invention to employ a plurality of impact spring biased plungers mounted on the housing of a floor finishing machine and operatively connected through rollers to a cam plate which is connected to the wear plate and to couple a pneumatic cylinder and piston to each of the plungers to control the vibrations imparted to the wear plate.

It is another feature of this invention to employ in a cement finishing machine a splined plate and a splined drive shaft to connect the wear plate to the prime mover mounted on the machine housing in rigid rotary relationship while permitting axial movement of the wear plate with respect to housing and thus reduce the vibrations imparted to the prime mover.

It is another feature of this invention to employ in a cement finishing machine a splined plate and a splined drive shaft to connect the prime mover with the wear plate and to mount a biasing spring between the splined shaft and the wear plate to prevent vibratory motion of the wear plate from being transmitted to the prime mover.

It is a further feature of this invention to employ in a cement finishing machine a stationary housing containing reciprocable spring biased plungers, a rotary plate having cam surfaces which engage rollers operatively connected to the plungers and a manually operable fluid pump connected to pistons mounted on the housing to move the housing with respect to the rotary plate and thus control the vibratory motion imparted to the plate by the plungers.

A complete understanding of this invention and of these and various other features thereof may be gained from a consideration of the following detailed description when read with the accompanying drawing in which:

FIGURE 1 is a plan view, partly in section, of one illustrative embodiment of this invention;

FIGURE 2 is a view in elevation taken along the line 22 of FIGURE 1;

FIGURE 3 is an enlarged view of the left hand portion of FIGURE 2;

FIGURE 4 is a detailed view taken long the lines 44 of FIGURE 3.

Referring now to the drawing, there is depicted one illustrative embodiment of this invention. A stationary cement finishing machine housing has a drive shaft 12 located substantially at the center of the housing. A wear plate 13 is rotatably mounted in housing 10 and is connected to master plate 14 by suitable bolts such as bolt 17, which bolts also secure cylindrical member 19 to master plate 14. Master plate 14 has two series of similar cam surfaces 15 and 16 adjacent the outer periphery of plate 14 which serve to store energy for the purpose of producing vibratory motion to plate 14 in a manner which will be subsequently explained. A splined plate 21 is mounted on cylindrical member 19 by means of bolts 23. Splines 25 on plate 21 engage the keyways of splines 27 on shaft 12. The splines on the shaft and plate permit axial movement of shaft 12 with respect to plate 21 while preventing relative rotary motion of shaft 12 with respect to plate 21 as will be explained in greater detail below. A shock absorber spring 29 is mounted in a recess in cylindrical member 19 and engages washer 31 which washer is mounted on the end of shaft 12 by means of bolt 33. The shock absorber spring 29 provides a means for preventing the transmission of the vibratory motion from wear plate 13 to the prime mover (not shown) mounted on the machine housing 10. Four cylinders 35 are shown mounted around the periphery of housing 10 above suitable apertures 36 in the housing by means of bolts 38. A fluid cylinder 40 is mounted above each cylinder 35 by means of suitable bolts 37. Reciprocating plungers 39 are positioned in apertures 36 beneath each of cylinders 35 and coupled through rollers 41 and shafts 45 to cam surfaces 15 and 16.

One of the plunger-cylinder assemblies will now be discussed in detail. As best seen in FIGURE 3, an impact spring 47 is held between a shoulder 49 of plunger 39 and a portion of housing 10 to force plunger 39 downward when spring 47 is depressed through the movement of the cam surfaces 15 and 16 past rollers 41. Piston shaft 51 is connected to plunger 39 by means of suitable bolts 53 and 55 and link assembly 57. Piston shaft 51 extends through cylinder 40 and has mounted thereon a piston 59 which has around its outer periphery a suitable pneumatic seal 61. Piston 59 is secured to shaft 51 by means of snap rings 63 and 65 which engage recesses in shaft 51. An annular plug 64 encircles shaft 51 and is threadably engaged in an aperture 66 in the lower wall of cylinder 40. A fluid sealing washer 68 is mounted in a recess in plug 64 and engages shaft 51 to prevent the leakage of fluid around shaft 51 from cylinder 40. A suitable fluid such as hydraulic liquid is pumped into cylinder 40 between the lower wall and piston 59 to force piston 51 upward and thus cause the rollers 41 to be disengaged from cam surfaces 15 and 16 and thus terminate the vibratory motion of the machine as will be subsequently explained. A drag compensating spring 67 is positioned between piston 59 and the upper wall of cylinder 40 to aid the return of the piston 51 after the fluid pressure is released. Vent holes 69 provide escape passages for air between piston 59 and the upper wall of cylinder 40. A key plate 49 is secured to housing 10 adjacent plunger 39 by means of a suitable nut 50. Key plate 48 has an extension or key 52 which engages a slot in plunger 39 to prevent rotation of plunger 39 in response to lateral forces transmitted from rollers 41.

A gear reducing box 71 is mounted above housing 10 by suitable means (not shown) and worm shaft 73 is coupled through a worm and wheel (not shown) to drive shaft 12. A suitable prime mover may be mounted on housing 10 and coupled to worm shaft 73 to provide a source of power for both the rotary and vibratory motion of the cement finishing machine.

A handle 81 is connected to housing 10 by means of angular plates 83 and bolts 85. A fluid pump 87 is mounted on handle 81 by means of straps 89. Pump 87 includes a piston (not shown) and a shaft 88 connected to the piston. A lever 91 is mounted on handle 81 by means of bracket 93 and connected to piston shaft 88. A valve control 97 is connected to a pressure release alve (not shown) in pump 87 to permit the operator to control the release of fluid pressure. A fluid coupling 99 is connected between piston 87 and piston 40 to permit fluid to be transmitted from pump 87 to cylinder 40 in response to the motion of lever 91.

Referring now to FIGURE 4, there is shown in greater detail, the cooperation of one roller 41 and cam surface 15. A similar cooperation takes place between the opposite roller 41 and cam surface 16. Cam surface 15 includes a substantially flat trough 100 and a peak or crest 102 at the termination of an incline plane 104 which is connected to trough 100. The entire length of a given cam surface is measured from one crest or peak to the next crest or peak and this length is termed the cam pitch. The extreme lower portion 106 of plunger 39 is disengaged from master plate 14 when rollers 41 ride up on one of the incline planes 104 as master plate 14 is rotated by the prime mover. When rollers 41 pass a crest 102 then the energy stored in spring 47 by the upward motion of rollers 41 is imparted to the plunger causing plunger extension 106 to strike master plate 14 as shown at 107 and thus impart vibratory motion each time rollers 41 pass a pair of crests 102-.

Advantageously, adjacentcylinders 35 are positioned diflerent peripheral distances from each other around the periphery of housing 10. For example, as best seen in FIGURE 1, cylinders 35A and 35C are positioned diametrically opposite each other while cylinder 35B is positioned a shorter peripheral distance from cylinder 35A than from cylinder 35C, and cylinder 35]) is diametrically opposite cylinder 35B. For best results, the difference in these peripheral distances is equal to one-half the cam pitch. Thus, with this arrangement the pistons 39 enclosed in cylinders 35B and 35D will be out of phase with the pistons in cylinders 35A and 35C. Thus a beat frequency will be developed greatly increasing the number of vibrations imparted to the master plate and thence to the wear plate without the necessity for rotating the wear plate at high speeds. In this particular instance, the beat frequency will be twice the frequency of reciprocation of a single piston. Other peripheral spacings may be employed to develop different frequencies and the number of plungers may be increased or decreased as desired. Similarly, a beat frequency may be developed by equally spaced plungers which cooperate with cam surfaces having different cam pitches about the periphery of the master plate, the particular location of different length cams depending on the particular location of the plungers.

When the operator desires to terminate the vibratory motion while continuing the rotary motion of the wear plate, he operates lever 91 to deliver fluid to cylinder 40 causing piston 59 to move upwardly thus moving rollers 41 out of engagement with cam surfaces and 16. While the reciprocating motion is terminated due to this disengagement, the rotary motion nevertheless continues through the coupling of the splined drive shaft 12 and splined plate 21. The operator may operate the pump 87 prior to starting the prime mover to reduce the initial load on the prime mover. Also, when the cement surface is substantially level, the vibratory motion may be discontinued and the rotary motion continued to achieve a finished surface. When it is desired to initiate the vibratory motion, the operator turns valve control 97 which releases the fluid pressure and spring 67 forces piston 59 downward causing the fluid to move through coupling 99 to pump 87 and causing the plunger rollers 41 to operatively engage cam surfaces 15 and 16.

In order to reduce the possibility of the entry of foreign matter between the housing 10 and master plate 14, the housing 10 has a flange 110 which overlaps cam surface 16. Wear plate 13 has a substantially vertical edge 115 while master plate 14 has a tapered edge 117. This combination of vertical and tapered edges acts to traject foreign matter from the machine and thus further reduce the possibility of its entry into the machine.

It is thus apparent that this simple cement finishing machine utilizes a single prime mover to impart rotary and selectively controlled vibratory motion to the cement. Another rotary and selectively controlled vibratory cement finishing machine is disclosed in our application Serial No. 682,717, filed September 9, 1957.

While the principles of this invention have been ex plained with reference to one illustrative example, it is understood that they may be applied to various other equivalent embodiments without departing from the spirit and scope of this invention.

We claim:

1. In a concrete finishing machine a housing, a master plate rotatably mounted in said housing and having cam surfaces on one side, a concrete contacting plate attached to the opposite side of said master plate, a plurality of spring biased plungers reciprocably mounted in said housing, the peripheral distance between certain adjacent plunger means being different from the peripheral distance between certain other adjacent plunger means, a

plurality of rollers mounted on said plungers at a point spaced from the ends of the plungers a distance less than the height of the said cam surfaces and greater than the distance between the bottom of said cam surface and said concrete contacting plate and positioned to engage said cam surfaces, the peripheral spacing between the said cam surfaces being such as not to coincide with the peripheral spacing of said plungers, and means for moving said plungers relative to said cam surfaces whereby said rollers are disengaged from said cam surfaces while said plate is rotated, said plunger means imparting asynchronous vibratory motion to said concrete contacting plate in response to the rotation of said cam surfaces.

2. In a concrete finishing machine in accordance with claim 1 wherein said plungers are positioned approximately degrees apart, the peripheral distance between certain adjacent plungers being different from the peripheral distance between certain other adjacent plungers.

3. In a concrete finishing machine in accordance with claim 2 wherein the difference in peripheral distance between certain adjacent plungers and the peripheral distance between certain other adjacent plungers is equal to approximately one-half the cam pitch of said cam surfaces whereby said plungers impart asynchronous vibratory motion to said concrete contacting plate.

4. In a concrete finishing machine in accordance with claim 1 wherein said means for moving said plungers relative to said plate includes a plurality of fluid enclosing cylinders mounted on said housing, a piston located in each of said last mentioned cylinders and each connected to a plunger, and a fluid pump coupled to said last mentioned plurality of cylinders to force fluid between said last mentioned pistons and said last mentioned cylinders whereby said rollers are disengaged from said cam surfaces.

5. A concrete finishing machine or the like comprising a stationary housing, a master plate rotatably mounted in said housing having a plurality of cam surfaces adjacent the periphery of on one side of said master plate and a concrete contacting plate attached to the opposite side of said master plate, spring biased plunger means mounted on said housing and operatively engaging said cam surfaces whereby vibratory motion is imparted to said master plate by said plunger means in response to the rotation of said master plate and means for selectively terminating the operative engagement between said plunger means and said cam surfaces comprising cylinder means mounted on said housing having piston means slidable therein, said piston means being connected to said plunger means, and fluid pump means coupled to said cylinder means for moving said piston means in a direction away from said master plate to terminate the vibratory motion imparted to said master plate while said master plate is rotating.

6. A device according to claim 5 wherein said cam surfaces are spaced around concentric circles with respect to the axis of said master plate and are spaced apart to permit said plunger means to engage said master plate therebetween, each of said plunger means having a roller mounted thereon to engage each of said cam surfaces and wherein said plunger means are spaced at different peripheral distances around the periphery of said housing whereby said master plate is subjected to high frequency asynchronous vibration upon actuation of said plungers.

References Cited in the file of this patent UNITED STATES PATENTS 1,550,102 Schlueter Aug. 18, 1925 2,034,942 Dodds Mar. 24, 1936 2,042,156 McCrery May 26, 1936 2,128,779 Knight Aug. 30, 1938 2,140,970 Reedy Dec. 20, 1938 2,289,247 Davis July 7, 1942 (Other references on following page) UNITED STATES PATENTS FOREIGN PATENTS 2,333,041 Poulter Oct. 26, 1943 113,320 Australia June 13, 1941 2,641,169 Ytterberg June 9, 1953 311,346 Switzerland Jan. 31, 1956 2,646,729 Godenir July 28, 1953 5 2,723,608 Jackson Nov. 15, 1955 2,757,588 Pollitz Aug. 7, 1956 OTHER REFERENCES 2,875,676 Theime t a Mar, 1959 Engmeermg News-Record, y 1955. p 

